this.Password.PasswordChanged += (g, e) => 谁能解释下

this.Password.PasswordChanged += (g, e) =>这句话中的(g,e)是什么意思,还有 => 这个符号起到什么作用..
具体程序如下..
this.Password.PasswordChanged += (g, e) =>
{
if (!System.Text.RegularExpressions.Regex.IsMatch((g as PasswordBox).Password, @"\S+"))
ValidatorPassword.ErrorMsg = "Requird";
else if ((g as PasswordBox).Password.Length > 25)
ValidatorPassword.ErrorMsg = "< 25 words";
else
ValidatorPassword.ErrorMsg = "";
};
最好能告诉我个大概就好勒..谢谢各位高手勒.